I have recently studied the Chazon Ish's work Emunah U'Vitachon and in the opening pages, the Chazon Ish displays a vast knowledge of human anatomy. Also, the Chazon Ish successfully mapped out a plan for a neurosurgeon to successfully complete an operation. Where did the Chazon Ish learn so much about human anatomy and medicine? Could it be that the Chazon Ish studied medical books?
As always, please cite your sources.